Assessing WiMedia UWB

It's time to take stock of Ultra-Wideband—what breakthroughs still lie ahead?

Stephen Wood | Oct 22, 2008

Now that WiMedia Ultra-Wideband (UWB)
products have been in the market for a
year, it’s time to assess its progress and its
future. Like most new technologies, there
has been more hype than most people would like and
some glitches upon introduction. On the positive side,
the glitches are being fixed, product support by manufacturers
is broad, and applications enabled by UWB’s
unique combination of capabilities are emerging.

TEETHING PROBLEMS? NOT ANYMORE
When the first Wireless USB (WUSB) products rolled
out, they delivered significantly lower throughput than
was expected. This was due to the way the products
were specified and the way they were implemented.

As with Wi-Fi and Ethernet, UWB was specified at
a signaling rate, 480 Mbits/s, as signaling rate is the
one value that gets closest to providing an apples-toapples
comparison between technologies. In practice,
the actual throughput users experience depends on
many factors, including protocol overhead, number of
users, RF environment, and application mix.

The delta between the 480-Mbit/s signaling rate and
the 50- to 80-Mbit/s throughput of the first products
disappointed some early adopters who did not understand
that this throughput was anomalous. Manufacturers
rushed to get UWB chips to market by plugging
the UWB chip into an existing USB 2.0 port.

Unfortunately, this meant that data had to be translated
from 2.0 to WUSB at the host and from WUSB
back to 2.0 at the hub/peripheral. While this made for
efficient time-to-market, it added substantial protocol
overhead to the solution.

In contrast, when WUSB is implemented natively,
the payload rate increases from 50 Mbits/s to approximately
260 Mbits/s (or 54% of the signaling rate).
Some Internet Protocol (IP) and proprietary protocol
implementations on UWB radios have exceeded 300
Mbits/s.

Long-term support for the technology is growing.
Several major PC OEMs have begun to deploy WUSBbased
products, including Dell, Lenovo, and Toshiba.
Confidential data suggests that others are likely to follow
in the near future.

UWB implementations are currently going through
the traditional price decay curve that every new product
experiences. Introductory prices for UWB chips were in
the $15 range. Within two to three years of introduction,
this is expected to fall to $4 or less. UWB is in the
middle of this decay period now, and further adoption
will occur as prices decrease.

APPLICATIONS
WiMedia members, who specialize in triple-play
communications, have raised the potential of using
UWB radio designs transmitting over coax as a highspeed
home network. Since this application can use
existing WiMedia designs, it has been fairly straightforward
to deploy the first products in this area.

While still very early, this could provide the necessary
bandwidth for the evolving service provider networks
in the home. Other emerging applications that
can take advantage of UWB’s high bandwidth have
also begun to garner attention.

With wireless docking, portable devices can connect
to wired platforms. Imagine a handheld device
docking with a set-top box to synch programming
captured previously. Docking protocols will enable this
content to be transferred quickly, with minimum customer
interaction.

Platforms can be used to track user consumption
of audio, video, and various services, allowing personalization
of the services from the provider according to
consumer preferences.

In augmented reality, the user can select a game
that is projected onto the game board as a heads-up
display tracks the player’s hands as the user moves
pieces in the game. The 3D graphical effects will require
several simultaneous video streams to and from
the set-top box.

These and other functions are enabled by the hundreds
of megabits of bandwidth offered by UWB.